NOx in atmosphere causes photochemical smog or acid rain. Therefore, exhaustion of NOx from a mobile emission source such as an automobile equipped with an internal combustion engine such as gasoline engine or diesel engine, which is one of NOx sources, has become a social problem. For this reason, investigation has been progressed in the direction of making a law and regulations on exhaustion amount of NOx severer in the future. Accordingly, development of a catalyst for the purification of exhaust gas has been attracted attention.
For example, it has been disclosed that NOx can be adsorbed by using zeolite having a noble metal supported thereon (Patent Literature 1). In addition, a catalyst having NOx storage effect which comprises calcium and platinum or palladium, has been proposed (Patent Literature 2).